Cryogenic rectification system with corona discharge feed air pretreatment

Abstract

A system including pretreating feed air for a cryogenic air separation plant wherein feed air is passed through an electric field, oxygen is ionized, and ionized oxygen reacts with hydrocarbons upstream of an adsorption prepurifier, and subsequent separation of the feed air by cryogenic rectification.

We claim: 
     
       1. A method for processing feed air for cryogenic rectification comprising: (A) passing feed air comprising hydrocarbons through an electric field, ionizing oxygen of the feed air to produce ionized oxygen, and reacting ionized oxygen with hydrocarbons to produce carbon dioxide and water vapor within the feed air;   (B) adsorbing carbon dioxide and water vapor from the feed air onto adsorbent to produce prepurified feed air;   (C) passing prepurified feed air into a cryogenic air separation plant and separating the prepurified feed air by cryogenic rectification to produce at least one of product oxygen and product nitrogen; and   (D) recovering at least one of product oxygen and product nitrogen from the cryogenic air separation plant.   
     
     
       2. The method of claim 1 wherein the electric field is established in the same location as where the reaction of ionized oxygen with hydrocarbons takes place. 
     
     
       3. The method of claim 1 wherein oxygen is ionized by passage through an electric field at a first location and the ionized oxygen is passed to a second location wherein the reaction of ionized oxygen with hydrocarbons takes place. 
     
     
       4. The method of claim 1 wherein the electric field is established in a volume containing particulate material with interstitial space between the particulate material, and the reaction of ionized oxygen with hydrocarbons takes place within the interstitial space. 
     
     
       5. The method of claim 1 wherein the electric field is established by a series of direct current pulses between a planar electrode and at least one point electrode. 
     
     
       6. Apparatus for processing feed air comprising: (A) a corona discharge reactor and means for passing feed air comprising hydrocarbons into the corona discharge reactor;   (B) an adsorption prepurifier and means for passing feed air from the corona discharge reactor to the adsorption prepurifier,   (C) a cryogenic air separation plant and means for passing feed air from the adsorption prepurifier to the cryogenic air separation plant; and   (D) means for recovering at least one of product oxygen and product nitrogen from the cryogenic air separation plant.   
     
     
       7. The apparatus of claim 6 wherein the corona discharge reactor comprises a volume filled with particulate matter held in place, at least in part, by electrodes, and wherein a high voltage alternating current source provides alternating current to the electrodes. 
     
     
       8. The apparatus of claim 6 wherein the corona discharge reactor comprises two spaced electrodes at least one of which is lined with dielectric material.